Noise reducing microphone apparatus

- Sony Corporation

A noise reducing microphone apparatus having an adaptive noise canceller which has a primary input and a reference input and in which the reference input is subtracted from the primary input through an adaptive filter and the adaptive filter is adaptively controlled by an output signal resulted from the subtraction, comprises. The apparatus includes a pair of microphone units disposed in proximate locations; and subtracting means for performing subtraction of outputs from the pair of microphone units. An output from one of the microphone units is supplied as the primary input of the adaptive noise canceller. A differential output from the subtracting means is supplied as the reference input of the adaptive noise canceller.

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Claims

1. A noise reducing microphone apparatus for reducing effects of wind noise on desired sounds comprising:

an adaptive noise canceller which has a primary input signal representing the desired sounds and the wind noise and a reference input signal representing only the wind noise and in which the reference input signal is passed through an adaptive filter and subtracted from the primary input signal and the adaptive filter is adaptively controlled by an output signal resulting from the subtraction;
a pair of microphone units disposed in close proximity to each other and each receiving the desired sounds and the wind noise, the output of one of the microphone units being supplied as the primary input signal to the adaptive noise canceller;
a single vibration detector for generating a vibration signal proportional to vibration affecting the pair of microphone units; and
adding and subtracting means for performing subtraction of output signals from the pair of microphone units and performing addition of said vibration signal to a result of the subtraction and producing an output supplied as the reference input signal to the adaptive noise canceller,
wherein an output from one of the microphone units is supplied as the primary input signal to said adaptive noise canceller and an output signal from the adding and subtracting means is supplied as the reference input signal to the adaptive noise canceler so that an output of the adaptive noise canceller has reduced wind noise effects.

2. The noise reducing microphone apparatus according to claim 1, further comprising:

a plurality of analog-to-digital converters receiving outputs respectively from the pair of microphone units and the vibration detecting means for producing digital outputs fed to the adaptive noise canceller and the adding and subtracting means; and
a digital-to-analog converter receiving the output of the adaptive noise canceller and producing an analog output signal therefrom.

3. The noise reducing microphone apparatus according to claim 1, further comprising:

a first analog-to-digital converter receiving the output of the one microphone unit and producing a digital signal fed to the adaptive noise canceller as the primary input signal;
a second analog-to-digital converter receiving the output of the adding and subtracting means and producing a digital signal fed to the adaptive noise canceller as the reference input signal; and
a digital-to-analog converter receiving the output of the adaptive noise canceller and producing an analog output signal therefrom.

Referenced Cited

U.S. Patent Documents

3803357 April 1974 Sacks
4427845 January 24, 1984 Yoshida
4658256 April 14, 1987 Piele
4912387 March 27, 1990 Moulds, III
4956867 September 11, 1990 Zurek et al.

Foreign Patent Documents

430513 May 1991 EPX
452103 June 1991 EPX

Other references

  • Patent Abstracts of Japan, vol. 14, No. 569, Dec. 18, 1990 (Aisin Seiki).

Patent History

Patent number: 5917921
Type: Grant
Filed: Apr 17, 1995
Date of Patent: Jun 29, 1999
Assignee: Sony Corporation (Tokyo)
Inventors: Tooru Sasaki (Tokyo), Masashi Ohkubo (Kanagawa)
Primary Examiner: Curtis Kuntz
Assistant Examiner: Ping W Lee
Attorney: Jay H. Maioli
Application Number: 8/424,581

Classifications

Current U.S. Class: 381/94; Directive Circuits For Microphones (381/92)
International Classification: H04B 1500;